1. Field of the Invention
The invention is directed to a method and apparatus for processing sheet material where individual sheets of the sheet material to be treated arrive in an arrival sequence, are distributed on two or more adjacently located conveying tracks, transported along the conveying tracks through a processing station and are resorted according to their original arrival sequence. More particularly, the invention is directed to a method and apparatus for the processing and development of photographic sheet material in a printer-paper processing combination arranged for single sheet processing.
2. State of the Art
A conventional minilab, equipped for processing of individual sheets, operates as follows: A single-sheet printer pulls photographic copying paper out of a cassette and cuts a sheet to a length corresponding to the format desired. The sheet is transported onto a paper stage where it is exposed in the proper image size and then removed. The exposed sheets are subsequently conveyed to a paper processor for development. The minilab processes different paper widths. In order to be able to fully utilize the paper processor in connection with narrow paper width, the sheets to be developed are conveyed or, transported on several tracks through the processor. The sheets, which are sequentially delivered from the printer, are distributed to the individual tracks of the paper processor by means of a transversal distributor. The papers are again collected in accordance with their original sequence at the output of the paper processor and stacked.
In known minilabs, the distribution of the sheets on the individual transport tracks of the paper processor takes place in accordance with a fixed cyclic sequence. Thus, in the case of three transport or, conveying tracks, every third sheet is directed to each of the tracks. Therefore, track 1 receives the first, fourth, seventh sheets and so on; track 2 receives the second, fifth, eighth sheets and so on; and track 3 receives the third, sixth, ninth sheets and so on. This fixed cyclic sequence is best suited for cases where sheets of the same size follow each other. However, if the sheets are of different length (for example, panorama format or APS film), large spaces are created between the sheets following each other on the individual transport tracks, and the paper processor is not fully utilized as these spaces are unused. As a result, productivity of the paper processor as well as the entire device is noticeably reduced.